outgoing pptp error 800 and 721

[scott]

Hi,

Im still having PPTP connection problems. Now outgoing PPTP gets error 800
and 721:

(Note: incoming PPTP gets error 721 sometimes)

---------------------------------------------------------
TESTING: Network 1 setup like this:
----------------------------------------------------------
0. Customer remote PPTP hosts
v
1. NET
v
2. Cable Modem
v
3. Netgear RP114
v
4. Netgear RP114 (supports IIS machine in front of firewall)
v
5. Zywal50 firewall
v
6. LAN

- I can establish a PPTP connection from client on 6 to PPTP host on 6. (so
pptp server ok)
- I can establish a PPTP connection from 4 to 6. (so firewall ok)
- I cannot establish a PPTP connection from 6 to 0 (but can from network 2
below)
- I cannot establish a PPTP connection from 4 to 0 (firewall out of
equation)
- Not tried 2 to 0 at moment.
- Net connection always up.
- Incoming FTP to my FTP server ok (from 0 to host on 6)
- Incoming IIS connections ok (from 0 to host on 4)

On 2000 and XP from 6 or 4 I get errors ranging from:
721 - no response related to GRE.
800 - unable to reach host.
(this is when attempting a pptp connection from internal 4 or 6 to external
0).



-------------------------------------------------------------
On another net connection i have network 2 setup like this:
-------------------------------------------------------------
0. Customer remote PPTP hosts
v
1. NET
v
2. Cable Modem
v
3. RP114
v
4. LAN


I can always establish a PPTP connection from 4 to 0, no problems at all via
this RP114 to customers. I only evey have the 721 error to my VPN server.

It must be releated to the configuration of one of the Netgear RP114 devices
on the 1st network as it happens in front of the firewall. But i have no
idea what ?

NOTE: Netgear support say they are 100% this router is GRE compataible.
NOTE: Applied MS regisrty fix in KB 271731
NOTE: win2k sp4 and XP sp1
NOTE: two network 1 and 2 have differnt public IPs but same ISP.
NOTE: ISP say they dont block GRE or PPTP

Thanks
Scott.

 

[scott]

One further point i failed to mention.

When establishing a sucessful PPTP connection my firewall reports PPTP and
GRE foward. When it fails with error 721 the GRE protocol is not reported
but PPTP is i.e GRE does not get as far as the firewall.

When running the PPTP connection from my server infront of the firewall but
behind both routers. PPTP and GRE is reports and i always get a connection
i.e one of the routers must be the problem.

Thanks
Scott.